mirror of
https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake.git
synced 2025-10-14 14:11:23 -04:00
52 lines
1.1 KiB
Go
52 lines
1.1 KiB
Go
package ipsetsink
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import (
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"crypto/hmac"
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"hash"
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"hash/crc64"
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"github.com/clarkduvall/hyperloglog"
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"golang.org/x/crypto/sha3"
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)
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func NewIPSetSink(maskingKey string) *IPSetSink {
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countDistinct, _ := hyperloglog.NewPlus(18)
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return &IPSetSink{
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ipMaskingKey: maskingKey,
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countDistinct: countDistinct,
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}
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}
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type IPSetSink struct {
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ipMaskingKey string
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countDistinct *hyperloglog.HyperLogLogPlus
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}
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func (s *IPSetSink) maskIPAddress(ipAddress string) []byte {
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hmacIPMasker := hmac.New(func() hash.Hash {
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return sha3.New256()
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}, []byte(s.ipMaskingKey))
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hmacIPMasker.Write([]byte(ipAddress))
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return hmacIPMasker.Sum(nil)
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}
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func (s *IPSetSink) AddIPToSet(ipAddress string) {
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s.countDistinct.Add(crc64FromBytes{hashValue(s.maskIPAddress(ipAddress))})
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}
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func (s *IPSetSink) Dump() ([]byte, error) {
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return s.countDistinct.GobEncode()
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}
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func (s *IPSetSink) Reset() {
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s.countDistinct.Clear()
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}
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type hashValue []byte
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type crc64FromBytes struct {
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hashValue
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}
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func (c crc64FromBytes) Sum64() uint64 {
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return crc64.Checksum(c.hashValue, crc64.MakeTable(crc64.ECMA))
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}
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